I'm trying to make a scene like this:

But no matter how I mess with the bounce settings in cycles; the light just isn't coming out of the other side of the prism:

What am i doing wrong?
I'm trying to make a scene like this:

But no matter how I mess with the bounce settings in cycles; the light just isn't coming out of the other side of the prism:

What am i doing wrong?
It was the "indirect light" in the "clamping" section of the "scene" properties tab. It needs to be set to 0 for light to go through the prism. I do not understand why it is so dark that that happens though.